Data storage systems are arrangements of hardware and software that may include multiple storage processors coupled to arrays of non-volatile storage devices. In typical operation, the storage processors service storage requests that arrive from users. The storage requests specify files or other data elements to be written, read, created, or deleted, for example. The storage processors run software that manages incoming storage requests and performs various data processing tasks to organize and secure user data stored on the non-volatile storage devices.
Data storage systems commonly store file systems that client machines can access for reading and/or writing over a network. Such data storage systems typically assign FSIDs (file system identifiers) to the file systems they host. The data storage systems may also provide file handles (e.g., NFS file handles) to client machines, to provide client machines with fast access to files in the file systems. A data storage system typically provides different file handles for accessing respective files in the various file systems it stores. A typical file handle includes an FSID, which identifies the file system in which a desired file can be found, a file identifier, such as an inode number of the file within the designated file system, and a generation count.